Power and starting system for engines



y 1954 e. A. DMITROFF ETAL 3,132,471

POWER AND STARTING SYSTEM FOR ENGINES Original Filed Jan. 8, 1960 4Sheets-Sheet l INVENTORS GEORGE A- DMI'TROFF EDGAR ROBITAILLE, JR-

AGENT y 1954 G. A. DMITROFF ETAL 3,132,471

POWER AND STARTING SYSTEM FOR ENGINES Original Filed Jan. 8, 1960 4Sheets-Sheet 2 AGENII" y 1964 G. A. DMITROFF ETAL 3,132,471

'F'OWER AND STARTING SYSTEM FOR ENGINES Original Filed Jan. 8, 1960FIC5-3 4 Sheets-Sheet 3 y 12, 1964 G. A. DMITROFF ETAL 3,132,471

POWER AND STARTING SYSTEM FOR ENGINES Original Filed Jan. 8, 1960 4Sheets-Sheet 4 INVE N TO RS GEO RGE A DM I T ROF'F EDGAR ROB l TA l L..E JR- United States Patent POWER AND STARTING SYSTEM FGR ENGINES GeorgeA. Dmitrotf, Trumbull, and Edgar Robitaille, Jr.,

Bridgeport, Conn., assignors to United Aircraft Corporation, EastHartford, Conn., a corporation of Delaware Continuation of applicationSer. No. 140,136, Sept. 22, 1961, which is a continuation of applicationSer. No. 1,240, Jan. 8, 1960. This application Sept. 21, 1962, Ser. No.225,431

19 Claims. (Cl. 60-6) This application is a continuation of copendingapplication Serial No. 140,136, filed September 22, 1961, which is acontinuation of application Serial No. 1,240, filed January 8, 1960,both now abandoned, and relates to a hydraulic operating system forengines which provides for starting of the engines and auxiliary powerfor driving engine accessories and other components.

An object of this invention is to make available electrical andhydraulic power without operating an aircraft propulsion unit.

Another object of this invention is to provide a system which canoperate when the aircraft is operating to take over the driving ofaccessories so that the aircraft propulsion unit has more poweravailable.

A further object of this invention is to provide a system which isoperable in low temperature ranges.

A further object of this invention is to provide a starting and powersystem which provides emergency fluid for actuation of accessories suchas landing gear.

Other objects and advantages will be apparent from the specification andclaims, and from the accompanying drawings which illustrate anembodiment of the invention.

FIGURE 1 is a perspective view of a helicopter having a powerplant withtwo jet engines for driving its rotor sys tem;

FIGURE 2 is a schematic view of the starting and power system;

FIGURE 3 is an enlarged View of the master control valve and secondarycontrol valve; and

FIGURE 4 is an enlarged view of the transmission unit connecting thegenerator and motor pump to the engine or main transmission.

While FIGURE 1 shows a helicopter having a specific configuration, it isto be understood that the power transmission means can be used on anytype of helicopter. Further, referring to FIGURE 1, a helicopter isshown having a body 2 which generally houses the pilot and cargo orpassenger compartments. The powerplant is shown located on top of thehelicopter comprising two gas turbine engines 4 and 6 which are mountedin a housing 8 in a side-by-side relationship. Their exhaust is directedfrom the side of the housing through openings 10. A main rotor pylon 12covers the power transmission system and extends between the housing 8and the body 2 of the helicopter. The main rotor head 14 is supported onthe upper end of an upright drive shaft 16 which extends upwardly fromthe power transmission system.

.This system is connected between said drive shaft and two gas turbineengines 4 and 6. A power transmission system which can be used in ahelicopter of this type is shown and claimed in U.S.Application SerialNo. 757,881, filed August 28, 1958, now patent No. 2,979,968 for a PowerTransmission System by Frederick C. Beurer. Rotor blades 18 are mountedon the rotor head in a usual manner. The helicopter may be controlled byany control mechanism desired; such a control mechanism is shown in thepatent to Alex, U.S. Patent No. 2,811,324. A rear pylon 21! extendsupwardly from the tail cone 22. A tall rotor 24 is mounted on saidpylon. Conventional forward landing gear 26 and rear landing gear 23 areshown thereon.

' 62 by a conduit 176. This secondary control valve 161 3,132,471Patented May 12, 1964 FIGURE 2 shows two hydraulic starter motors 3t}and 32 connected through overrunning clutches 34 and 36, respectively,to cooperating starters on engines 4 and 6. These clutches are providedto disengage the hydraulic motors from the engines at a predeterminedspeed. The inlet to the hydraulic starter motor 30 is attached to oneoutlet of a two-way selector valve 46 by conduit 48. The inlet of thehydraulic starter motor 32 is connected to the other outlet of thetwo-way selector valve 46 by conduit 50. The outlet of the hydraulicstarter motor 30 is connected to the inlet of a check valve 52 byconduit 54 and the outlet of the hydraulic starter motor 32 is connectedto the inlet of a check valve 56 by conduit 58. Each out let of thecheck valves 52 and 56 is connected to a reservoir 60 by conduit 62.Reservoir 66 may be vented to atmosphere or pressurized, depending onthe type of system used.

An accumulator 76 is connected to the selector valve 46 by a conduit'78, a master control valve 1th) and a conduit 72. A secondary controlvalve 101 is connected to the master control valve 1111) in a manner tobe hereinafter described.

An auxiliary power unit has a motor/pump unit 152 which is connected tothe master control valve by con duit 15-1. Motor/pump 152 is connectedto a second motor/pump unit 156 by conduit 158. Motor/pump 156 isconnected to the secondary control valve 1111 by conduit 16%. Thismotor/pump 156 is drivingly connected to either the main transmissionaccessories or the engine accessories in a manner to be hereinafterdescribed. Conduit 158 is also connected to the secondary control valve101 by conduit 162.

Reservoir 60 has an outlet connected to conduit 154 by conduit 164. Thisconduit 164 has a filter 61 and a check valve 166 located therein. Thecheck valve 166 permits flow only from reservoir 60 to conduit 154. Aconduit 168 connects conduit 164 at a point between reservoir 61 and theinlet to check valve 166 to conduit 158. A conduit 188 connects conduit164 and quick disconnect 136. Conduit 168 has a check valve 170 locatedtherein which permits flow only from conduit 164 to conduit 158. A handpump 128 has its inlet connected to conduit 16 1 by conduit 172 and hasits outlet connected to conduit 162 by a conduit 174.

Secondary control valve 161 is connected to conduit is also connected toa pressure reducer valve 94 by conduit 178. The outlet of the pressurereducer valve, giving the desired reduced pressure, is connected to autility system by a conduit 91 which, in a helicopter, operates suchdevices 93 as taxi gear motors, cargo hoisting mechanisms, blade foldingmeans, landing gear actuators, and nose door actuators. This pressurereducer valve is also connected to conduit 62 by a conduit 18%) whichpermits any excess to be returned to the reservoir 60. A pressurereducer valve is unnecessary if the output pressure from the secondarycontrol valve through conduit 178 is satisfactory for operation of thehydraulic devices of the utility systern. The outlets of the utilitydevices are connected to conduit 62 by a conduit 95.

A pressure relief valve 182 has its inlet connected to conduit 162 by aconduit 184 and has its outlet connected to conduit 62 by a conduit 186.

A provision for external operation of this system is the location ofhydraulic inlet and outlet connectors in the system so that an externalhydraulic pump can be connected thereto. An inlet connector 131) isshown connected to conduit 162 by conduit 187 and an outlet connector136 is shown connected to conduit 16 1 by conduit 188. These connectorscan be of the quick connect-disconnect type to provide for speed andease of connection.

Master control valve 100 is connected to conduit 186 by conduit 190.This master control valve is also connected to conduit 158 by conduit192.

The master control valve 100 and the secondary control valve 101 areinterconnected by a conduit 194 and an electrical mechanical device 196.The interconnection of these two valves, 180 and 101, is clearly shownin FIG- URE 3. An emergency bypass valve 198 is connected betweenconduit 78 and conduit 91.

Motor/pump 156 is fixed to transmission unit 200 by means of bolts 202.The splined operating shaft 264 of the motor/pump 156 is positioned inan internally splined receptacle 206 located in the end of a shaft 298.Shaft 208 is mounted for rotation in the transmission unit 200 bybearing units 210 and 212 on opposite sides of the unit. The end of theshaft 298 having the splined receptacle is open to the exterior of thetransmission unit and has a sealing member 214 positioned between thefree end of the shaft and the transmission unit. A gear 216 is formedintegrally with the shaft 208. While the gear is shown integrally formedwith the shaft, the two may be fixedly connected by any means desired.Gear 216 meshes with a second gear 218 which is also mounted forrotation in the transmission unit 290.

Gear 218 is integrally formed with a shaft 220 which is mounted inbearing units 222 and 224. The end of the shaft 220 extending away fromengine 6 is formed having an internally splined receptacle 226. Asealing member 228 is positioned between the free end of the shaft 220and transmission unit 208. The other end of shaft 220 is formed as aone-way drive mechanism 238. This mechanism is formed having a shaft 232extending therefrom which is mounted for rotation in the transmissionunit 2110. Bearing unit 234 and a sealing member 236 are providedbetween this shaft 232 and the transmission unit. The shaft 232 has asplined end which extends into engine 6 and is drivingly connected tothe drive shaft of the engine.

As shown in FIGURE 2, a generator 238 is shown fixed to the transmissionunit 200. While only a generator has been shown, other gears can bemounted in the transmission unit 288 to mesh with gears 216 or 218 todrive other units.

The one-way drive mechanism 231 is so arranged that when motor/pump 156is being driven as a motor, the shaft 284 in turn drives the gear 218,and any other gear which may be connected thereto, in order to drive thegenerator and any other mechanically driven unit which may be connectedto any additional gears. This driving movement by motor/pump 156 willnot drive shaft 232. However, when the engine has been started and isrunning, it will drive shaft 232 to in turn drive the generator 238 andany other mechanically driven unit connected to the gear 218 and willdrive the motor/ pump 156 so that it will act as a pump.

The master control valve 108 includes a housing 258 having two valves252 and 254 located therein. Valve 252 comprises a cylindrical bore 256in housing 250 with a piston member 258 slidably mounted therein. Pistonmember 258 is formed having two lands 260 and 262. Land 260 cooperateswith the end of conduit 72 which extends through housing 250. Both ofthe lands 26d and 262 serve to guide the piston member within thecylindrical bore 256. Valve 252 has a stem 264 which extends externallyof said housing. The valve 252 is biased to a closed position by aspring 266 which acts between the housing 250 and a flange 268 on stem264. The external portion of stem 264 forms part of a solenoid 271 whichmoves valve 252 to its open position when energized. This solenoid 270is energized in a manner to be hereinafter described.

Valve 254 comprises a cylindrical bore 272 in housing 250 with a pistonmember 274 slidably mounted therein. Piston member 258 is formed havingtwo lands 276 and 278. Land 276 cooperates with the end of conduit 154which extends through housing 250 and land 278 cooperates with the endof conduit 192 which extends through housing 251). The end of conduitwhich extends through housing 250 opens into the cylindrical bore 272between the ends of conduits 154 and 192. Both of these lands serve toguide the piston member within bore 272. Valve 254 has a stem 280 whichextends externally of said housing. The valve 254 is biased to a closedposition by a spring 282 which acts between the housing 250 and a flange284 on stem 280. The external portion of stem 28%) forms part of asolenoid 286 which moves valve 252 to its open or downward position whenenergized. This solenoid 286 is energized in a manner to be hereinafterdescribed.

Each of the cylindrical bores 256 and 272 are connected by a passageway288 at a point below lands 262 and 278, respectively, when the valvesare biased to their upward position. Passageway 288 is connected to theend of conduit 194 which extends into housing 250 by a check valve 290which permits flow only from conduit 194 into passageway 288. Passageway288 is connected with the end of conduit 78 which extends into housing255) by a passageway 292. Passageway 292 is connected to the top of eachcylindrical bore 256 and 272 by pas sageways 294 and 296, respectively.A double-pole double-throw switch 298 is provided which energizes in oneposition a solenoid 27 (i and in its other position energizes thesolenoid 286, and in both positions a solenoid 299 is operated for apurpose which is to be hereinafter described.

The electrical mechanical device 196 includes a double pole double-throwswitch 298. This switch is connected at each of its poles 348 and 342 toone terminal of a power source 344. This power source 344 has anotherconnection to ground. When the switch 298 is placed in its Eng.position, the poles 340 and 342 are con nected respectively to terminals346 and 348. Terminal 348 is connected by an electrical line 350 to thecoil of the solenoid 2741. The coil has another connection to ground.Terminal 346 is connected by an electrical line 352 to the coil of thesolenoid 299. The coil of this solenoid 299 is also connected to ground.When the switch 298 is placed in its A.P.U. position, the poles 349 and342 are connected respectively to terminals 354 and 356. Terminal 356 isconnected by an electrical line 358 to the coil of the solenoid 286.This coil has another connection to ground. Terminal 354 is connected tothe electrical line 352.

The secondary control valve 101 includes a housing 305 having acylindrical bore located in each end thereof having coincidinglongitudinal axes. Cylindrical bore 392 forms part of a blocking valveand bore 304 forms part of a relief valve. in cylindrical bore 302 formovement therein and a piston 308 is positioned in bore 304 for movementtherein. Pistons 386 and 398 are interconnected by shaft 310 whichpasses through an opening 312 in the center of housing 306. A spring 314is located in bore 302 around shaft 310 between the upper end of thebore 302 and the upper face of piston 386. This biases the pistons 386and 358 downwardly. Piston 308 is formed having two lands 322 and 324.

A rod 316 extends from the upper face of piston 308 through the upperend of bore 304 and housing 300 to the exterior thereof. An annularholding member 318 is positioned on the free end of rod 316 for apurpose to be hereinafter described. The upper face of holding member318 is rounded or beveled such as at 320.

The electrical mechanical device 196 includes a mechanical latchingmechanism with a latch 390 having a hook 392 with a rounded end 394. Thelatch is mounted on a fixed pivot at 396. This pivot 396 is located onbracket 398 which is in turn fixed to aircraft structure. The latch 39%is positioned in line with annular holding member 318 so that therounded or beveled face 320 of A piston member 306 is mounted 'isconnected to bore 370 is the member will engage the rounded end 394 ofthe latch to earn the latch to the right and place the annular holdingmember 318 over the hook 392 when the piston 308 is moved to its fullupward position.

The free end of the latch 390 which extends upwardly from the pivot 396is connected to the moving core of the solenoid 299 by a rod 400. Aspring 402 is located around the rod 400 between a fixed collar 404 onsaid rod and the housing 406 of the solenoid 299 which is fixed toaircraft structure. This spring biases the latch 390 to its positionshown in FIGURE 3. A stop 408 is fixed to aircraft structure andprovides a positioning means against which spring 402 biases the freeend of latch 390.

The end of conduit 194 which extends into housing 300 is connected by apassageway 326 to the cylindrical bore 304 at a point just above land322 in its upward position. Conduit 160 extends into housing 300 andengages the surface of bore 304 at a point adjacent the annular spacebetween lands 322 and 324 when the piston 308 is located in its upwardposition. Conduit 162 extends into housing 300 and engages the surfaceof bore 304 at a point adjacent land 322 when piston 308 is located inits upward position. Passageway 326 is connected to the lower face ofcylindrical bore 304 by passageway 328.

Passageway 328 is connected into bore 302 at a point adjacent thecylindrical side surface. of the piston 306 when it is in its springbiased position downwardly. When piston 308 is in its downward position,the end of conduit 194 is open into the annular space between lands 322and 324. Conduit 160 engages the surface of bore 304 at a point adjacentland 324 when piston 308 is located in its downward position and conduit162 engages the surface of bore 304 at a point adjacent the annularspace between lands 322 and 324 when the piston 308 is located in itsdownward position.

A third bore 370 is located in the housing 300 having a longitudinalaxis parallel to the axis of bores 302 and 304. A piston member 372 islocated in said bore 370 having two pistons 374 and 376 interconnectedby a rod 378. The rod 378 is of such length as to provide a valve actionto be hereinafter described. Means are provided in bore 370 for sealingthe piston rod 378 so that there is no fluid leakage between the twosections of the bore 370. A sealing ring 380 has been shown located inan annular projection 382. A spring 282 is located around the piston rod378 between the upper face of the piston 376 and the lower face of theannular projection 382. This action biases piston member 372 to itsdownward position.

A passageway 384 connects the bore 302 adjacent its midpoint to bore 370at a point covered by the side of piston 376 when it is in its bottomspring biased position. When piston 306 is in its upward position andhooked position, passageway 328 is connected to passageway 384. Conduit178 enters housing 300 and is connected to bore 370 at a point coveredby the side of piston 376 when it is in its spring biased position. Whenthe piston 376 is in its upward position in bore 370, passageway 384 isconnected to'conduit 178.

A passageway 386 connects the bore 304 to bore 370. This passageway 386enters bore 304 at a point which is covered by land 322 when piston 308is located in its downward position. When piston 308 is in its upwardposition, the passageway 386 is open to the bore 304; as piston 308moves downwardly and the holding member 3118 is caught by hook 392, theland 322 covers passageway 386. Conduit 176 enters housing 300 and at apoint covered by the side of piston 374 when itis'in its spring biasedposition. Passageway 386 opens into bore 370 at a point just belowpiston 374 when the piston is in its spring biased position downwardly.When piston 376 is in its upward position, passageway 386 is connectedto conduit 176.

6 Operation In this system, the accumulator may be charged by the handpump 128, motor/ pump 152, motor/pump 156, or by an external pump unitattached to connectors and 136. If this system is just being placed inoperation, or the accumulator is not charged for some other reason, thehand pump 128 may be operated to charge said accumulator. First, themovable pistons 306 and 308 of the secondary control valve 101 arelocated in their down position, if they are not already in thatposition; and, second, the switch 298 is located in its normally openposition. Hand pump 128 then pumps fluid through conduit 172 and conduit164 from reservoir 60 through conduit 174 to conduit 162. Fluid inconduit 162 can pass only to the secondary control valve 101 since it isblocked from flowing in any other direction. This fluid then passesaround the annular groove in piston 308 to passageway 326. From thispoint, the fluid passes through conduit 194, check valve 290, passageway292 and conduit 78 to the accumulator 76. As the pressure built up bythe hand pump 128 reaches the pressure at which piston members 308 and306 start to rise, this pressure being determined by the force of spring314, the charge in the accumulator is sufficient for its operation. Thiscan be indicated to the pilot by a gauge 49 or some other indicatingmeans.

Anotherway to charge the accumulator is by the use 'of an external pumpconnected to the inlet and outlet connectors 130 and 136, respectively.Here again, pistons 306 and 308 are located in their downward positionand switch 298 is located in its normally open position. In thisarrangement, the outlet of the external pump will discharge intoconnector 130 and through conduits 187 and 162 into the annular spacearound piston 308. From this point, the fluid passes to the accumulator76 in the same manner as it does with the hand pump 128. Connector 136is connected to conduit 164 by conduit 188 which provides a fluidsupply. This external pump can also remain in operation to actuate theengine accessories and the hydraulic devices. This pump can also startthe A.P.U. if it has a high enough capacity.

In starting the auxiliary power unit (A.P.U.) the pilot will placeswitch 298 in its A.P.U. position. This closing of switch 298 energizessolenoids 286 and 299. The energizing of solenoid 286 will move valve254 to its downward position so that conduit 78 is connected to conduit154 and conduit 192 is connected to conduit 190. This permits theaccumulator 76 to be connected to the motor/ pump 152.

The path of flow from the accumulator will be through conduit 78,passageway 296, valve 254, conduit 154, motor/pump 152 acting as amotor, conduit 192, annular groove of valve 254, conduit 190, conduit186 and conduit 62 to the reservoir 60. Immediately after the auxiliarypower is started, it is allowed to warm up with the switch in its A.P.U.position. The fluid being pumped will follow a path of least resistance.The energizing of solenoid 299 will move latch 390 to a position so thatthe hook 392 will not be in the path of holding member 318. If theholding member is held by the hook, it will be released so that pistons306 and 308 may be biased to their downward position. This will occur ifthe pressure below piston 308 drops in value. It is necessary thatpiston 308 be in its downward position for subsequent recharging of theaccumulator in preparation for the next use thereof. 1

When the switch 298 is returned to an open position after A.P.U.warm-up, as shown in FIGURE 3, valve 254 is returned to its upwardposition by spring 282 and latch 390 will be movedto its holdingposition by spring 402 since the solenoids 286 and 299 will bede-energized.

With the de-energization of solenoid 286 and therefore the movement ofvalve 254 to its upward position, the flow from conduit 78 to conduit154 and the flow from conduit 192 to conduit 190 is shut off. The pathof fluid through motor/pump 152 acting as a pump is now through conduit158, conduit 162, the annular groove around piston 308 to passageway326. The fluid then passes to the accumulator by the same path as setforth above. When the accumulator charge reaches a predetermined value,the pressure of the fluid in passageway 328 acts on the bottom of piston308 to move the pistons 366 and 308 and holding member 318 to its upwardposition. It can be seen from this action that the accumulator has beenrecharged and that the path of flow from motor/pump 152 is now throughconduit 158, motor/pump 156 acting as a motor, conduit 160, the annulargroove around piston 398, passageway 326, and passageway 328 to conduit178. Motor/pump 156 will be acting to drive the generator and any othermechanically driven units connected thereto. The flow then passesthrough a pressure reducer valve Q4 which sends fluid at the properpressure through conduit 91 to the hydraulic devices 93. Excess pressureis passed through pressure reducer valve 94 to conduit 180 to conduit 62where it is directed to the reservoir 60. The outlet of the hydraulicdevices 93 is connected to conduit 62 by conduit 94. This shows how theA.P.U. 150 can drive the engine accessories and the aircraft hydraulicdevices without using the aircraft power plant propulsion unit.

In starting the engines on the helicopter shown in FIG- URE 1, the pilotwill position the selector valve 46 to select whichever engine hedesires to start first. Assuming he desires to start engine 6 first, theselector valve 46 will be placed in the position shown in full lines inFIGURE 2. Switch 2% will then be placed in its Eng. position. Thisclosing of switch 298 energizes solenoids 270 and 299. The energizing ofsolenoid 270 will open valve 252 so that passageway 294 is connected toconduit 72. This permits the accumulator 76 to be connected to thestarter motor 32, along with the output of the motor/ pump 152. If theaccumulator is charged, it will discharge to the starter 32.

The path of flow from the accumulator will be through conduit 78,passageway 294, valve 252, conduit 72, valve 46 and conduit 50. Theenergizing of solenoid 299 will move latch 3% to a position so that thehook 392 will not be in the path of holding member 318. If the holdingmember is held by the hook, it will thereby be released so that pistons306 and 3&8 may be biased to their downward position if the pressurebelow piston 368 drops. 'It is necessary that piston 368 be in itsdownward position to insure the flow from the motor/ pump 152 asdescribed above through conduit 162. Further, it is necessary that thisvalve be in this position for subsequent recharging of the accumulatorin preparation for the next use thereof.

When the next engine, engine 4, is to be started, the selector valve isplaced in the position shown in dotted lines in FIGURE 2. The operationdescribed above for the starting of engine 6 holds for engine 4.

When the engines are running and the A.P.U 150 is oil, the motor/pump156 acts as a pump and drives the hydraulic devices 93 through conduit160, secondary valve 101 and therethrough conduit 178, pressure reducervalve 94 and conduit 91. During this operation, the generator and otherconnected mechanically driven units will be driven by the engines. if atleast one engine is running and it is necessary to charge theaccumulator, this can be done through the motor/pump 156. The gear box200 can be connected to an engine or the main transmission of anaircraft. It is advisable that the gear box be driven through bothengines such as through the main transmission as a safety measure.

When either or both of the engines are running, the A.P.U. can bestarted to drive the generator and other mechanically driven units alongwith the hydraulic devices, thus unloading the engine or engines.

It is to be understood that the invention is not limited to the specificdescription above or to the specific figures,

but may be used in other ways without departure from its spirit asdefined by the following claims.

We claim:

1. In combination, a main engine, a hydraulic starting motor drivinglyconnected to said main engine, an auxiliary engine, a first hydraulicmotor/ pump drivingly connected to said auxiliary engine, anaccumulator, first valved means connecting said accumulator to saidfirst hydraulic motor/pump to drive said motor/pump as a motor to startsaid auxiliary engine, second valved means connecting said accumulatorto said hydraulic motor to drive said motor to start said main engine, atransmission unit, an engine accessory drivingly connected to saidtransmission unit, first means connecting said main engine to saidtransmission unit for driving it, a second hydraulic motor/ pump, secondmeans connecting said second hydraulic motor/pump to said transmissionunit for power transmission therebetween, and third means connectingsaid first hydraulic motor/ pump to said second hydraulic motor/pump foroperating said second motor/ pump as a motor when said first hydraulicmotor/ pump is operating as a pump to dnive said transmission unit andtherefore said accessory.

2. In combination, a main engine, a hydraulic starting motor drivinglyconnected to said main engine, an auxiliary engine, a first hydraulicmotor/pump drivingly connected to acid auxiliary engine, an accumulator,first valved means connecting said accumulator to said first hydraulicmotor/pump to drive said motor/pump as a motor to start said auxiliaryengine, second valved means connecting said accumulator to saidhydraulic motor to drive said motor to start said main engine, atransmission unit, an engine accessory drivingly connected to saidtransmission un-it, first means connecting said main engine to saidtransmission unit for driving it, a second hydraulic motor/pump, secondmeans connecting said second hydnaulic motor/pump to said transmissionunit for power transmission therebetween, third means connecting saidfirst hydraulic motor/ pump to said second hydraulic motor/ pump foroperating said second motor/ pump as a motor when said first hydraulicmotor/ pump is operating as a pump to drive said transmission unit, ahydraulically operated device, and fourth means connecting said secondhydraulic motor/ pump to said hydraulically operated device foroperating said device when said second hydraulic motor/ pump isoperating as a pump.

3. In combination, a engine, a hydraulic starting motor drivinglyconnected to said main engine, an auxiliary engine, a first hydraulicmotor/ pump drivingly connected to said auxiliary engine, anaccumulator, first valved means connecting said accumulator to saidfirst hydraulic motor/pump to drive said motor/pump as a motor to startsaid auxiliary engine, second valved means connecting said accumulatorto said hydraulic motor to drive said motor to start said main engine, atransmission uni-t, an engine accessory drivingly connected to saidtransmission unit, first means connecting said main engine to saidtransmission unit for driving it, a second hydraulic motor/pump, secondmeans connecting said second hydraulic motor/pump to said tranrnsissionunit for power transmission therebetween, third means connecting saidfirst hydraulic motor/pump to said second hydraulic motor/pump foroperating said second motor/pump as a motor when said first hydraulicmotor/pump is operating as a pump to drive said transmission unit, ahydraulically operated device, fourth means connecting said secondhydraulic motor/pump to said hydraulically operated device for operatingsaid device when said second hydraulic motor/pump is operating as apump, and fifth means connecting said first hydraulic motor/pump to saidhydraulically operate-d device for operating said device when said firsthydraulic motor/ pump is operating as a pump. V

4. In combination, a main engine, a hydraulic starting motor drivinglyconnected 'to said main engine, an auxiliary engine, a first hydraulicmotor/pump drivingly connected to said auxiliary engine, an accumulator,first valved means connecting said accumulator to said first hydraulicmotor/pump to drive said motor/pump as a motor to start said auxiliaryengine, second valved means connecting said accumulator to saidhydraulic motor to drive said motor to start said main engine, atransmission unit, an engine accessory drivingly connected to saidtransmission unit, first means connecting said main engine to saidtransmission unit for driving it, a second hydraulic motor/pump, secondmeans connecting said second hydaulic motor/pump to said transmissionunit for power transmission therebetween, third means connecting saidfirst hydraulic motor/pump to said second hydraulic motor/pump foroperating said second motor/pump as a motor when said first hydraulicmotor/ pump is operating as a pump to drive said transmission unit, ahydraulically operated device, fourth means connecting said secondhydraulic motor/pump to said hydraulically operated device for operatingsaid device when said second hydraulic motor/pump is operating as apump, fifth means connecting said first hydraulic motor/pump to saidhydraulically operated device for operating said device when said firsthydraulic motor/ pump is operating as a pump, and third valved meansconnecting said accumulator to said hydraulically operated device tooperate said device.

5. In combination, a main engine, a hydraulic starting motor drivinglyconnected to said main engine, an auxiliary engine, a first hydraulicmotor/pump drivingly connected to said auxiliary engine, an accumulator,first valved means connecting said accumulator to said first hydraulicmotor/pump to drive said motor/pump as a motor to start said auxiliaryengine, second valved means connecting said accumulator to saidhydraulic motor to drive said motor to start said main engine, atransmission unit, an engine accessory drivingly connected to saidtransmission unit, first means connecting said main engine to saidtransmission unit for driving it, a second hydraulic motor/pump, secondmeans connecting said second hydraulic motor/ pump to said transmissionunit for power transmission therebetween, third means connecting saidfirst hydraulic motor/ pump to said second hydraulic motor/pump foroperating said second motor/pump as a motor when said first hydraulicmotor/pump is operating as a pump to drive said transmission unit, andthird valved means in one position connecting said first hydraulicmotor/pump to said accumulator when said second hydraulic motor/pump isoperating as a pump to charge said accumulator, a hydraulically operateddevice, said third valved means in another position connecting saidsecond hydraulic motor/pump to said hydraulically operated device tooperate said device when said second hydraulic motor/pump is operatingas a pump.

6. In combination, an engine, a hydraulic motor operatively' connectedto said engine, an auxiliary engine, a first motor/pump operativelyconnected to said auxiliary engine, a first conduit means between saidhydraulic motor and said motor/pump, valve means in said first conduitmeans, a source of fluid under pressure operatively connected to saidvalve means, an engine accessory operatively connected to said engine, asecond motor/pump operatively connected to said engine accessory, andsecond conduit means between said first and second motor/ pumps, saidvalve having means to direct fluid under pressure from said source todrive said first motor/pump to start said auxiliary engine and drivesaid second motor/ pump by the fluid discharged from said first motor/pump, said valve also having means to direct fluid from said firstmotor/pump to said hydraulic motor when said auxiliary engine hasstarted to start said main engine whereby said engine will drive saidsecond motor/pump means as a pump.

7. In combination, an engine, a hydraulic motor operatively connected tosaid engine for starting it, an auxiliary engine, a motor/pumpoperatively connected to said auxiliary engine for starting it and beingdriven thereby, drive means connected between said hydraulic motor andsaid motor/pump, said drive means having a fluid outlet connected tosaid hydraulic motor, an engine accessory operatively connected to saidengine to be driven thereby, motor means operatively connected to saidengine accessory to drive said accessory, conduit means between saidmotor/pump and said motor means for driving said motor means when saidmotor/pump is operating as a pump, an accumulator, valved means todirect fluid under pressure from said accumulator to drive saidmotor/pump to start said auxiliary engine, said motor/ pump drives saidmotor means by the fluid discharged therefrom to drive said accessory,said drive means having valved means to direct fiuid to said outlet forsaid hydraulic motor when said auxiliary engine has started to startsaid main engine whereby said engine will drive said accessory.

8. In combination, first power plan means for providing a main source ofpower, said first means including a main engine, an auxiliary engine,second means con nected to said auxiliary engine for starting saidauxiliary engine, an engine accessory, third means operably connectingsaid main engine and said engine accessory for driving said accessory,fourth means operably connecting said auxiliary engine and said mainengine for starting said main engine, fifth means operably connectingsaid auxiliary engine and said engine accessory for driving saidaccessory, a hydraulically operated device, sixth means operablyconnecting said main engine and said hydraulically operated device fordriving said device, and seventh means operably connecting saidauxiliary engine and said hydraulically operated device for driving saiddevice.

9. In combination, first power plant means for providing a main sourceof power, said first means. including a main engine, an auxiliaryengine, second means con nected to said auxiliary engine for startingsaid auxiliary engine, third means operably connecting said auxiliaryengine and said main engine for starting said main engine, an engineaccessory, fotuth means operably connecting said main engine and saidengine accessory for driving said accessory, a hydraulically operateddevice, fifth means operably connecting said main engine and saidhydraulically operated device for operating said device, and sixth meansoperably connecting said auxiliary engine with said engine accessory andsaid hydraulically operated device for operating said accessory anddevice.

10. In combination; first power plant means for providing a main sourceof power; said first means including a main engine; an auxiliary engine;second means for starting said auxiliary engine; third means forstarting said main engine; an engine accessory, fourth means operablyconnecting said main engine and said engine accessory for driving saidaccessory; fifth means operably connecting said second means forstarting said auxiliary engine and said engine accessory for drivingsaid accessory; an accumulator; and valved means for directing fluidfrom said accumulator to said second means for starting said auxiliaryengine. 7

11. In combination; first power plant means for providing a main sourceof power; said first means including a main engine; an auxiliary engine;second means for starting said auxiliary engine; an engine accessory;third means for starting said main engine driven by said auxiliaryengine; fourth means operably connecting said main engine and saidengine accessory for driving said accessory; said second means includinga hydraulic motor/ pump connected to said auxiliary engine, anaccumulator, and valved means for connecting said accumulator to saidhydraulic motor/pump to drive said motor/pump as a motor; said thirdmeans including said hydraulic motor/ pump, a hydraulic motor connectedto said main engine to start it, and valved means for connecting saidmotor/ til pump to said hydraulic motor to drive said hydraulic motorwhen said motor/pump is operating as a pump; and fourth means operablyconnecting said motor/pump with said engine accessory for driving saidaccessory when said motor/ pump is operating a pump.

12. In combination; first power plant means for providing a main sourceof power; said first means including a main engine; an auxiliary engine;second means for starting said auxiliary engine; an engine accessory;third means for starting said main engine, fourth means operablyconnecting said main engine and said engine accessory for driving saidaccessory by said mam engine; said second means including a hydraulicmotor/pump connected to said auxiliary engine, an accumulator, andvalved means for connecting said accumulator to said hydraulic motor/pump to drive it as a motor to start said auxiliary engine; fifth meansoperably connecting said motor/ pump with said engine accessory fordriving said accessory by said auxiliary engine; a hydraulicallyoperated device; sixth means operably connecting said main engine andsaid hydraulically operated device for driving said device; and seventhmeans operably connecting said motor/pump and said hydraulicallyoperated device for driving said device.

13. In combination; first power plant means for providing a main sourceof power; said'first means including a main engine; an auxiliary engine;second means for starting said auxiliary engine; an engine accessory;third means connecting said auxiliary engine to'said main engine forstarting said main engine; fourth means operably connecting said mainengine and said engine accessory for driving said accessory; said secondmeans including a hydraulic motor/pump connected to said auxiliaryengine, an accumulator, and valved means for connecting said accumulatorto said hydraulic motor/pump; a hydraulically operated device; fifthmeans operably connecting said main engine and said hydraulicallyoperated device for operating said device; and sixth means operablyconnecting said motor/pump with said engine accessory and saidhydraulically operated device for operating said accessory and device.

14. In combination; first power plant means for providing a main sourceof power; said first means includ-- ing a main engine; an auxiliaryengine; second means for starting said auxiliary engine; third means forstarting said main engine by said auxiliary engine; an engine accessory;fourth means operably connecting said main engine and said engineaccessory for driving said accessory; said second means including ahydraulic motor/pump connected to said auxiliary engine, an accumulator,and valved means for connecting said accumulator to said hydraulicmotor/pump to direct fluid to said motor/ pump; fifth means operablyconnecting said motor/ pump with said engine accessory for driving saidaccessory; and sixth means operably connecting said motor/pump to saidaccumulator to charge said accumulator.

15. In combination; first power plant means for providing a main sourceof power; said first means including a main engine; an auxiliary engine;second means for starting said auxiliary engine; third means connectedto said auxiliary engine for starting said main engine; an engineaccessory; fourth means operably connecting said main engine and saidengine accessory for driving said accessory; said second means includinga hydraulic motor/ pump connected to said auxiliary engine, anaccumulator, and valved means for connecting said accumulator to saidhydraulic motor/pump; said engine accessory having a hydraulic motormeans operably connected thereto; and fifth means operably connectingsaid motor/ pump With said hydraulic motor means for driving saidaccessory.

16. In combination, a main engine, a hydraulic starting motor drivinglyconnected to said main engine, an auxiliary engine, a hydraulicmotor/pump drivingly connected to said auxiliary engine, an accumulator,first valved means connecting said accumulator to said hydrau licmotor/pump to drive said motor/pump as a motor, a transmission unit, anengine accessory, means connecting said engine accessory to saidtransmission unit to be driven thereby, first means connecting said mainengine to said transmission for driving it, hydraulic motor means,second means connecting said hydraulic motor means to said transmissionunit for driving it when said motor/ pump is operating as a pump, thirdmeans connecting said hydraulic motor/ pump to said hydraulic motormeans for operating said hydraulic motor means when said hydraulicmotor/ pump is operating as a pump to drive said transmission unit, andfourth means connecting said motor/ pump to said hydraulic startingmotor for driving it when said motor/pump is operating as a pump, saidfourth means including a valve for directing a fluid to said hydraulicmotor.

17. In combination, a main engine, a hydraulic starting motor drivinglyconnected to said main engine, an auxiliary engine, a hydraulicmotor/pump drivingly connected to said auxiliary engine, an accumulator,first valved means connecting said accumulator to said hydraulicmotor/pump to drive said motor/pump as a motor, a transmission unit, anengine accessory, means connecting said engine accessory to saidtransmission unit to be driven thereby, first means connecting said mainengine to said transmission for driving it, hydraulic motor means,second means connecting said hydraulic motor means to said transmissionunit for driving it when said motor/pump is operating as a pump, thirdmeans connecting said hydraulic motor/pump to said hydraulic motor meansfor operating said hydraulic motor means when said hydraulic motor/pumpis operating as a pump to drive said transmission unit, and drive meansconnecting said motor/pump to said hydraulic starting motor for drivingit when said motor/pump is operating as a pump, said drive means havinga fluid outlet, said drive means having a valve for controlling the flowof fluid through said outlet to said hydraulic starting motor.

18. In combination; first power plant means for providing a main sourceof power; said first means including a main engine; an auxiliary engine;second means for starting said auxiliary engine; an engine accessory;third means for starting said main engine driven by said auxiliaryengine; fourth means operably connecting said main engine and saidengine accessory for driving said accessory; said second means includinga hydraulic motor/ pump connected to said auxiliary engine, anaccumulator, and valved means for connecting said accumulator to saidhydraulic motor/pump to drive said motor/pump as a motor; said thirdmeans including said hydraulic motor/pump, a hydraulic motor connectedto said main engine to start it, and valved means for connecting saidmotor/pump to said hydraulic motor to drive said hydraulic motor whensaid motor/pump is operating as a pump; and fourth means operablyconnecting said motor/pump with said engine accessory for driving saidaccessory when said motor/ pump is operating as a pump; a hydraulicallyoperated device, fifth means operably connecting said motor/pump withsaid hydraulically operated device for operating it; sixth meansoperably connecting said main engine with said hydraulically operateddevice for operating it.

19. In combination; a main engine; an auxiliary engine; first'means forstarting said main engine and said auxiliary engine; an engineaccessory; second means operably connecting said main engine and saidengine accessory for driving said accessory; said first means includinga hydraulic motor/ pump drivingly connected to said auxiliary engine, afirst hydraulic motor drivingly connected to said main engine, anaccumulator, and first valved fluid conduit means for connecting saidaccumulator to said hydraulic motor/pump for starting said auxiliaryengine; said engine accessory having a second hydraulic motoroperablyconnected thereto; third means operably connecting saidmotor/pump with said second hydraulic 3,132,471 13 14- motor for drivingsaid accessory; a hydraulically opersaid second valved means directing afluid therethrough ated device; fourth means operably connecting saidmain from said second hydraulic motor to said hydraulically engine andsaid hydraulically operated device for driving operated device inanother position.

said device; and fifth means operably connecting said References Citedin the file of this patent motor/ pump to said accumulator forrecharging said 210- 5 cumulator; said fifth means including secondvalved UNITED STATES PATENTS means; said second valved means directing afluid there- 2,557,933 Beaman et a1 June 26, 1951 through to saidaccumulator to recharge it in one position; 2,906,088 Clark Sept. 29,1959

1. IN COMBINATION, A MAIN ENGINE, A HYDRAULIC STARTING MOTOR DRIVINGLYCONNECTED TO SAID MAIN ENGINE, AN AUXILIARY ENGINE, A FIRST HYDRAULICMOTOR/PUMP DRIVINGLY CONNECTED TO SAID AUXILIARY ENGINE, AN ACCUMULATOR,FIRST VALVED MEANS CONNECTING SAID ACCUMULATOR TO SAID FIRST HYDRAULICMOTOR/PUMP TO DRIVE SAID MOTOR/PUMP AS A MOTOR TO START SAID AUXILIARYENGINE, SECOND VALVED MEANS CONNECTING SAID ACCUMULATOR TO SAIDHYDRAULIC MOTOR TO DRIVE SAID MOTOR TO START SAID MAIN ENGINE, ATRANSMISSION UNIT, AN ENGINE ACCESSORY DRIVINGLY CONNECTED TO SAIDTRANSMISSION UNIT, FIRST MEANS CONNECTING SAID MAIN ENGINE TO SAIDTRANSMISSION UNIT FOR DRIVING IT, A SECOND HYDRAULIC MOTOR/PUMP, SECONDMEANS CONNECTING SAID SECOND HYDRAULIC MOTOR/PUMP TO SAID TRANSMISSIONUNIT FOR POWER TRANSMISSION THEREBETWEEN, AND THIRD MEANS CONNECTINGSAID FIRST HYDRAULIC MOTOR/PUMP TO SAID SECOND HYDRAULIC MOTOR/PUMP FOROPERATING SAID SECOND MOTOR/ PUMP AS A MOTOR WHEN SAID FIRST HYDRAULICMOTOR/PUMP IS OPERATING AS A PUMP TO DRIVE SAID TRANSMISSION UNIT ANDTHEREFORE SAID ACCESSORY.